Insulating material



Feb. 5, 1935.

c. KOHLER INSULATING MATERIAL Filed Dec. '7. 1929 r Patented Feb. 5, 1935 UNITED sraxras PATENT OFFICE Application December 7, 1929, Serial No. 412,405

In Switzerland December 12, 1928 Claims. (01. 154-44) The present invention relates to an insulating material made of artificial textile fibres, particularly of artificial silk, and its object is to provide a material of this kind which not only has good 5 insulating properties but also is light as well as pliant and therefore easily mouldable so that it maybe shaped as desired. In order to obtain may be so chosen that the fabric can be easily.

- woven or knitted. The insulating material according to the present invention may be used to great advantage owing to its pronounced suppleness in every case in which narrow hollow spaces or spaces of intricate shape have to be efiectively insulated.

Although it is known that exhausted hollow 5 spaces are good insulators and that, for instance,

silk is a good insulating material, the proposal to provide thread-shaped bodies with a core space that is void of air for the purpose of obtaining an effective insulating material which is at the same 30 time pliable and susceptible of being given any shape is an original idea far from being commonplace and of suflicient importance to motive patentability.

The invention will now be explained with reference to the accompanying drawing. hi the drawing:

Fig. 1 shows in a longitudinal section and on an enlarged scale a thread-shaped body having. a core space void of air and subdivided by partitions into cells,

Fig. 2 shows diagrammatically an installation for producing the insulating material according to the invention from artificial silk, some parts of the installation being shown in section, others in an elevation view, and

Fig. 3 shows in elevation an evacuating device to which simultaneously several thread-like bodies made of insulating material may be connected.

In Fig. 1 is shown a thread or filament 1 made of artificial silk which comprises an air-tight shell and a core-space which is free of air. The latter is subdivided into cells 2 by transverse walls 3. Such a subdivision of the hollow space by transverse walls presents the advantage that with a rupture of the thread the vacuum is not destroyed over the whole length of the thread but only in the cell 2 through which the rupture passes. The. transverse walls 3 further increase the rigidity of the filament. Consequently the evacuated core-space maybe increased at the expense of the thickness of the air-tight shell 1 whereby the insulating properties are increased.

Fig. 2 shows in a diagrammatic manner an installation for producing a thread-like body of artificial silk having an evacuatedjcore space defined by an air-tight shell, and means for forming transverse walls thereby to subdivide the core space of the body. The artificial silk, from which the thread-like body is to be made, is supplied by means of a conduit 5 in the liquid state 15 to the container 4. In order to prevent the mass in the container 4 from solidifying the latter is surrounded by a heating device 6 to which the heating medium is supplied by the conduit '7 and led on by the conduit 8. The discharge of the 20 mass from the container 4 is controlled by an adjustable nozzle needle 9. The nozzle in which the needle 9 is arranged ends in a space 10 in which a vacuum is produced by means of an air pump 11. The space 10 is closed in an air-tight manner by a liquid column 12 whereby the height h will varyin accordance with the vacuum present in the space 10. The mass flowing past the nozzle needle 9 is shaped in the space 10 as a. thread-like hollow body 16; its core-space is thereby free of. air. This hollow body 16 is squeezed at regular intervals by means of ro-' tating rollers 13, 14 provided withprojections 15 at their circumference and being driven from a pulley-17, for the purpose of obtaining transverse walls 18 which subdivide the hollow space in the body 16 into cells. The hollow body 16 which has passed the liquid column 12 is wound on a reel 19.

Fig. 3 illustrates the manner in which thread- 40 like hollow bodies 20, having an air-tight shell q and which are closed in an air-tight manner at their. lower ends are suspended from heads 21, which are connected to the suction space of an air pump 22. By means of this evacuating device it is possible to exhaust the air from the hollow core of the bodies 20; care should be taken to close the bodies 20 before they are removed from the heads 21.

I claimi 1. An insulating material comprising a hollow filament of artificial silk, transverse walls subdividing the hollow space into cells, each of which is evacuated the Walls of the cells being of sumcient strength and of such length as to prevent collapse of the said core-spaces under atmospheric pressure and permanently maintaining the evacuated cells.

2. An insulating material made of artificial silk fibres, and comprising a hollow filament having core-spaces which are substantially free of air and having an air-tight shell, the walls of the core-spaces being sufiiciently short to prevent collapse of the said core-spaces under atmospheric pressure and permanently maintaining the air-free core spaces. 1

3. An insulating material made of artificial silk fibres, and having the shape of a hollow filament the core-space of which is free of air and subdivided by transverse walls into cells and the shell is air-tight, the walls of the core-spaces,

being sufiiciently short to prevent collapse of the said core-spaces under atmospheric pressure and permanently maintaining the air-free corespaces.

4. An insulating material made of artificial silk fibres, said fibres comprising a continuous air-tight external wall having a series of evac- .uated spaces within said wall and a series of transverse walls between said evacuated spaces for preventing communication and collapse of said evacuated spaces.

5. An artificial silk fiber for the fabrication of insulating material which comprises an external,

air-tight wall provided with a series of transverse walls, said air-tight and transverse walls forming hollow spaces having an internal pressure substantially smaller than atmospheric pressure, said walls adapted to withstand the external atmospheric pressure without collaps- CONRAD KOHLER.- 

